This invention relates to an exhaust flange gasket which seals the interface between an exhaust manifold and an exhaust pipe, wherein the gasket has a spherical sealing portion.
The prior art has traditionally sealed an interface between an exhaust manifold and an exhaust pipe with coined ring gaskets. This type of gasket is somewhat expensive and difficult to manufacture, and in some cases has reduced the strength of the connection between the exhaust manifold and the exhaust gasket. Typically, the prior art gaskets have had frusto-conical surfaces facing mating surfaces on both the exhaust manifold and the exhaust pipe.
In another known exhaust construction, the exhaust manifold has a generally spherical surface which contacts a generally spherical surface on an exhaust pipe in metal to metal contact. Recent tightening of the emission standards established by government regulations have rendered that the metal to metal contact insufficient however, and thus this construction is no longer adequate.
In one known gasket for use in an exhaust coupling, a gasket member has spherical surface facing a surface on a first exhaust pipe and a fiat surface contacting a surface on a second exhaust pipe. This type of gasket, while having some beneficial characteristics, does not allow misalignment between the two pipes with continued contact.